Some rootkit/viruses can hide in places where they simply cannot be detected and will keep reappearing.
The only safe solution is to backup your personal data.
Reformat the drive and do a clean OS install.
Install antivirus and malwarebytes.
Install all OS and antivirus updates.
Scan the drive that has your personal data with the antivirus and malwarebytes.
Copy your personal data back onto your system.